Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756332Ab1BRJ5M (ORCPT ); Fri, 18 Feb 2011 04:57:12 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:51775 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740Ab1BRJ5J (ORCPT ); Fri, 18 Feb 2011 04:57:09 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=MuyN6jn3PKe2sEStJorxIgF+4SGIUjybBI/QxHpwpPlZ/23n735KYUxnC4xoeZRHog mn7vsXh6jGxl+uRcQEC6gBbWQfdSRUaGMiv+GG3gDoKp+goYBMqdoOeOIrZzxEfgCQy4 LHCSPvFDpeDZFxYDNVf7jMnWKKwtT9aq7cdR0= Subject: [PATCH] net: Add default_advmss() methods to blackhole dst_ops From: Eric Dumazet To: George Spelvin , David Miller Cc: linux-kernel@vger.kernel.org, netdev , Roland Dreier In-Reply-To: <1298010735.2642.9.camel@edumazet-laptop> References: <20110218050321.10415.qmail@science.horizon.com> <1298010735.2642.9.camel@edumazet-laptop> Content-Type: text/plain; charset="UTF-8" Date: Fri, 18 Feb 2011 10:57:03 +0100 Message-ID: <1298023023.2595.170.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5436 Lines: 143 Le vendredi 18 février 2011 à 07:32 +0100, Eric Dumazet a écrit : > Le vendredi 18 février 2011 à 00:03 -0500, George Spelvin a écrit : > > But wonder of wonders, kernel mode switching worked so I got to see the > > oops on the text-mode console. It happened just as I tried to ssh out. > > > > CC netdev (removed linux-netdev) > > I'll take a look this morning, thanks for the report. > > > It's a Core 2 duo laptop (Dell E1405), 2 GB RAM, running a 32-bit kernel. > > It's worth noting that I was using wired internet (b44 driver) and > > not wireless. > > > > I've been having a lot of weird lockups with 2.6.38-rcX, quite a change > > from the very stable 2.6.36, but this is the first time I booted -rc5. > > Also, the symptoms are very different; before the lockup did not seen > > correlated with any particular activity, but the "lockup" was more like > > something getting wedged in the kernel that more and more tasks would > > get stuck on until everything stopped responding. > > > > I should mention that this is transcribed by hand from the screen. > > Oh, and also, it is far from the first time I ran ssh this boot. > > (I re-tested it ater rebooting, just to be sure. Not a consistent > > crash.) > > > > Anyway, jumping to address 0 looks "interesting", so it seems worth reporting. > > > > BUG: unable to handle kernel NULL pointer dereference at (null) > > IP: [< (null)>] (null) > > *pde = 00000000 > > Oops: 0000 [#1] SMP > > last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/uevent > > Modules linked in: rfcomm btusb sco l2cap crc16 bluetooth b43 mac80211 cfg80211 [last unloaded: sha256_generic] > > > > Pid: 12178, comm: ssh Not tainted 2.6.38-rc5 #227 Dell Inc. MXC061 /0MG532 > > EIP: 0060:[<00000000>] EFLAGS: 0021246 CPU: 0 > > EIP is at 0x0 > > EAX: f5947e00 EBX: f5982f80 ECX: 00000024 EDX: c148fe00 > > ESI: f5947e00 EDI: ebf29e54 EBP: ebf29ee0 ESP: ebf29dd0 > > DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 > > Process ssh (pid: 12178, ti=ebf28000 task=ebefc6c0 task.ti = ebef28000) > > Stack: > > c12c83ea 07e2427d 02000000 7b018f79 c117b827 0b996609 7b018f79 5f5f6644 > > f5982f80 00000000 ebf29e58 ebf29ee0 c12cc0e0 00001600 00000000 00000001 > > 03641600 00000000 00000000 00000000 00000000 036423c0 3e6423c0 00000000 > > Call Trace: > > [] ? tcp_connect+0xdd/0x3fd > > [] ? secure_tcp_sequence_number+0x4f/0x65 > > [] ? tcp_v4_connect+0x3c1/0x417 > > [] ? inet_stream_connect+0x88/0x1fc > > [] ? _copy_from_user+0x2b/0x10e > > [] ? sys_connect+0x70/0x98 > > [] ? get_empty_filp+0x9f/0x121 > > [] ? alloc_file+0xf/0x85 > > [] ? sock_alloc_file+0x97/0xeb > > [] ? fd_install+0x1b/0x38 > > [] ? sock_map_fd+0x1b/0x20 > > [] ? sys_socketcall+0x9d/0x291 > > [] ? sysenter_do_call+0x12/0x26 > > Code: Bad EIP value > > EIP: [<00000000>] 0x0 SS:ESP 0068:ebf29dd0 > > CR2: 0000000000000000 I suspect following patch is needed CC Roland Dreier because he fixed the default_mtu problem in commit ec831ea72ee5d7d47 (net: Add default_mtu() methods to blackhole dst_ops) Thanks ! [PATCH] net: Add default_advmss() methods to blackhole dst_ops Commit 0dbaee3b37e118a (net: Abstract default ADVMSS behind an accessor.) introduced a possible crash in tcp_connect_init(), when dst->default_advmss() is called from dst_metric_advmss() Reported-by: George Spelvin Signed-off-by: Eric Dumazet CC: Roland Dreier --- net/ipv4/route.c | 7 +++++++ net/ipv6/route.c | 6 ++++++ 2 files changed, 13 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 788a3e7..5edb605 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2712,6 +2712,12 @@ static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst) return 0; } +static unsigned int ipv4_blackhole_default_advmss(const struct dst_entry *dst) +{ + return 256; +} + + static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) { } @@ -2722,6 +2728,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = { .destroy = ipv4_dst_destroy, .check = ipv4_blackhole_dst_check, .default_mtu = ipv4_blackhole_default_mtu, + .default_advmss = ipv4_blackhole_default_advmss, .update_pmtu = ipv4_rt_blackhole_update_pmtu, }; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 1c29f95..2eeeabb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -118,6 +118,11 @@ static unsigned int ip6_blackhole_default_mtu(const struct dst_entry *dst) return 0; } +static unsigned int ip6_blackhole_default_advmss(const struct dst_entry *dst) +{ + return 256; +} + static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) { } @@ -128,6 +133,7 @@ static struct dst_ops ip6_dst_blackhole_ops = { .destroy = ip6_dst_destroy, .check = ip6_dst_check, .default_mtu = ip6_blackhole_default_mtu, + .default_advmss = ip6_blackhole_default_advmss, .update_pmtu = ip6_rt_blackhole_update_pmtu, }; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/